Background: The microbial evolution of the J’ben Elgafs prepared with raw milk from local cows, was studied during the manufacturing and maturating process in order to characterize this variety of cheese from the Algerian terroir.Methods: The microbial activity and physical-chemical parameters were tested during the three dairy seasons of the year. Total, lactics and alteration floras were counted on their selective environments.Result: Lactic germs multiply considerably during the first days and only stabilize towards the end of maturation. The low presence of alteration floras is the result of the continuous modification of the physico-chemical parameters of Aw and pH from one stage to the other of the j’ben production and the respect of good processing practices. These different proportions of variation are induced by the biochemical reactions and microbial interactions that take place responsible for the sequential growth of one microbial group compared to another.